aop编程注解开发

本是古典何须时尚 2022-05-08 00:40 173阅读 0赞

注解开发比较方便

## 配置 ##

需要将项目中的aspectj和aspectjweaver更换为和jdk版本一样的版本  
比如我的jdk是1.8，就换为aspectj-1.8.jar和aspectjweaver-1.8.jar，  
至于怎么找这个头疼的事，不用去csdn上什么坑人的资源下载，直接去  
maven的中央仓库找就行了，使用见下面连接  
[https://blog.csdn.net/weixin\_36957153/article/details/82964828][https_blog.csdn.net_weixin_36957153_article_details_82964828]

记得删除就版本，不然会出错  
还得在xml里加上

<context:component-scan base-package="aop编程"/>
    
    
    <aop:aspectj-autoproxy  proxy-target-class="true"/>

ps：proxy-target-class="true"后来加上去的，是为了spring使用aspectj代理，而不是  
使用其默认的麻烦的jdk代理，不然得多写几个接口  
为了方便，我在测试类里加入  
@RunWith(SpringJUnit4ClassRunner.class)  
@ContextConfiguration(“classpath:/aop编程/aopTest.xml”)  
/\*  
有以上的注解，我们就可以直接在类上进行对象注入  
Spring整合Junit  
\*/

先放下代码

## 测试类 ##

package aop编程;
    
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.test.context.ContextConfiguration;
    import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
    
    import javax.annotation.Resource;
    
    /**
     * Created by Administrator on 2018/10/7.
     */
    @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration("classpath:/aop编程/aopTest.xml")
    /*
    有以上的注解，我们就可以直接在类上进行对象注入
    Spring整合Junit
     */
    public class testDemo {
    
        @Resource(name="deleUser")
        private userDao user;
    
        @Test
        public void testDemo1(){
            user.add("小明");
            user.deleUser("小明");
            user.update("小明");
            user.save();
        }
    
    
    }

## aopTest.xml ##

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xmlns:aop="http://www.springframework.org/schema/aop"
           xmlns:context="http://www.springframework.org/schema/context"
           xsi:schemaLocation="http://www.springframework.org/schema/beans
                         http://www.springframework.org/schema/beans/spring-beans.xsd
                         http://www.springframework.org/schema/aop
                         http://www.springframework.org/schema/aop/spring-aop.xsd
                         http://www.springframework.org/schema/context
                         http://www.springframework.org/schema/context/spring-context.xsd">
        
        
        <context:component-scan base-package="aop编程"/>
    
        
        <aop:aspectj-autoproxy  proxy-target-class="true"/>
    
        <bean id="deleUser" class="aop编程.userDao"></bean>
     
    </beans>

## userDao 用户代码，被增强的类 ##

package aop编程;
    
    /**
     * Created by Administrator on 2018/10/7.
     */
    public class userDao {
        public boolean deleUser(String name){
            System.out.println(name+"被成功删除deleUser");
            return true;
        }
    
        public void update(String name){
            System.out.println(name+"被更新update");
        }
    
        public void save(){
            System.out.println("调用userDao.save().....");
            int num=1/0;
        }
    
        public String add(String name){
            System.out.println(name+"被添加进来add");
            return "aaaaa";
        }
    }

## 切面类 ##

package aop编程;
    
    import org.aspectj.lang.JoinPoint;
    import org.aspectj.lang.ProceedingJoinPoint;
    import org.aspectj.lang.annotation.*;
    import org.omg.CORBA.Object;
    import org.springframework.stereotype.Component;
    
    /**
     * Created by Administrator on 2018/10/7.
     * 切面类
     */
    @Component
    @Aspect
    /*
    声明切面类为bean
    @Aspect  切面类
    * */
    public class aspect {
    
        @Pointcut("execution(* aop编程.userDao.add(..))")
        private void myPointcut(){
            //相当于切点<aop:pointcut expression="execution(* aop编程.userDao.add(..))" id="pointcut2"/>
            //为切面类指定切点
        }
    
        //通知可以直接在方法上写
        @Before(value = "execution(* aop编程.userDao.deleUser(..))&&args(name)")
        public void before1(JoinPoint joinPoint,String name){
            System.out.println(name+"dele执行前的检测..."+joinPoint);
        }
    
        //也可以为方法指定上面写好的切点方法,同样，returning要和方法的参数一样
        @AfterReturning(value = "myPointcut()",returning = "result")
        public void after1(String result){
            System.out.println("执行add方法后..."+result);
        }
    
        @Around("execution(* aop编程.userDao.update(..))")
        public Object around(ProceedingJoinPoint joinpoint) throws Throwable {
            System.out.println("调用update方法前");
            Object obj= (Object) joinpoint.proceed();
            System.out.println("调用update方法之后");
            return obj;
        }
    
        @AfterThrowing(value = "execution(* aop编程.userDao.save(..))",throwing = "ex")
        public void afterThrow(Throwable ex){
            System.out.println("异常被抛出...."+ex.getMessage());
        }
    
        @After("execution(* aop编程.userDao.save(..))")
        public void finals(){
            System.out.println("异常最终被通知");
        }
    }

这些通知详见上篇博客  
[https://blog.csdn.net/weixin\_36957153/article/details/82959424][https_blog.csdn.net_weixin_36957153_article_details_82959424]

## 前置通知 ##

@Before(value = “execution(\* aop编程.userDao.deleUser(…))&&args(name)”)  
加上&&args(name)是为了获取被增强方法的*参数*  
相当于在xml配置了pointcut和切面类(@Component和@Aspect就是声明为  
切面类bean交给Spring管理)

## 后置通知 ##

@Pointcut("execution(* aop编程.userDao.add(..))")
        private void myPointcut(){
            //相当于切点<aop:pointcut expression="execution(* aop编程.userDao.add(..))" id="pointcut2"/>
            //为切面类指定切点
        }
    
    //也可以为方法指定上面写好的切点方法,同样，returning要和方法的参数一样
        @AfterReturning(value = "myPointcut()",returning = "result")
        public void after1(String result){
            System.out.println("执行add方法后..."+result);
        }

这是另一种指定通知方法（同上）

## 环绕通知 ##

@Around("execution(* aop编程.userDao.update(..))")
        public Object around(ProceedingJoinPoint joinpoint) throws Throwable {
            System.out.println("调用update方法前");
            Object obj= (Object) joinpoint.proceed();
            System.out.println("调用update方法之后");
            return obj;
        }

## 异常通知 ##

@AfterThrowing(value = "execution(* aop编程.userDao.save(..))",throwing = "ex")
        public void afterThrow(Throwable ex){
            System.out.println("异常被抛出...."+ex.getMessage());
        }

## 最终通知 ##

@After("execution(* aop编程.userDao.save(..))")
        public void finals(){
            System.out.println("异常最终被通知");
        }

运行：  
![在这里插入图片描述][70]

ok，perfect

[https_blog.csdn.net_weixin_36957153_article_details_82964828]: https://blog.csdn.net/weixin_36957153/article/details/82964828
[https_blog.csdn.net_weixin_36957153_article_details_82959424]: https://blog.csdn.net/weixin_36957153/article/details/82959424
[70]: /images/20220508/738e9dfcc666409a8dba65a85d1874d6.png